Wiring (wire-pulling) rules for automatic fire alarm systems: protective conduit selection, conductor voltage rating and burning performance (not below B2), installation combinations, and workmanship (GB 50116-2013, GB 55036-2022, GB 50166-2019)

Topic Positioning

This card consolidates the complete rule chain for wiring/wire-pulling in automatic fire alarm systems (FAS): design level (protective conduit and cable selection, installation mode, circuit combinations) + construction/acceptance level (separate wiring, joints, conductor colors, junction boxes, insulation resistance, fill ratio), per current standards GB 55036-2022, GB 50116-2013, and GB 50166-2019. For compliance judgment of "how to pull and what to pull" in design, construction, supervision, and costing.

Core Conclusions

1. Cable selection

1. Burning performance (current mandatory requirement, GB 55036-2022 Clause 12.0.16): "The power-supply circuits and fire-linkage control circuits of automatic fire alarm systems shall use fire-resistant copper wires/cables with burning performance not below B2; the alarm bus, fire emergency broadcast, fire-telephone and other transmission circuits shall use copper wires/cables with burning performance not below B2." (Power and linkage-control circuits = fire-resistant and >= B2; alarm bus and other transmission circuits = >= B2.)
2. Voltage rating (GB 50116-2013 Clause 11.1.1): "Transmission circuits of automatic fire alarm systems and control circuits supplied below 50 V shall use copper insulated wires or copper cables with a voltage rating not below AC 300/500 V. Supply and control circuits using AC 220/380 V shall use copper insulated wires or copper cables with a voltage rating not below AC 450/750 V."
3. Minimum cross-section (GB 50116-2013 Clause 11.1.2): conductor section selection for transmission circuits shall, besides meeting the alarm equipment's technical conditions, satisfy mechanical-strength requirements; the minimum cross-sections of copper insulated wires and copper cables shall not be less than Table 11.1.2 (values per that table).

2. Protective conduit and installation mode

1. General provision (GB 50116-2013 Clause 11.2.1): "Transmission circuits of automatic fire alarm systems shall be protected by metal conduit, flexible (metal) electrical tubing, rigid plastic conduit of Class B1 or above, or enclosed raceways." Rigid plastic conduit of Class B1 or above shall meet the burning test requirements of GB/T 5169.14-2007.
2. Concealed vs exposed (GB 50116-2013 Clause 11.2.3): "Concealed runs shall be protected by metal conduit, flexible (metal) electrical tubing, or rigid plastic conduit of Class B1 or above, laid within non-combustible structural layers with a cover preferably not less than 30 mm; exposed runs shall be protected by metal conduit, flexible (metal) electrical tubing, or enclosed metal raceways. Mineral-insulated non-combustible cables may run exposed directly." Acceptance matches (GB 50166-2019 Clause 3.2.2): "Concealed ducts shall be laid within non-combustible structure with cover not less than 30 mm."
3. Circuit combination (GB 50166-2019 Clause 3.2.12): "The system shall be wired separately. Unless required by the design, circuits of different loops, different voltage classes, and AC vs DC of the system shall not be run in the same conduit or the same raceway compartment." Also (GB 50116-2013 Clause 11.2.6): "In horizontal conduit runs, except the alarm bus, circuits of different fire compartments shall not enter the same conduit."
4. Version note: GB 50116-2013 Clause 11.2.5 (cables of different voltage classes shall not share a conduit; when sharing a raceway it shall have dividers) was superseded from 2022-01-01 by GB 55036-2022; before citing Chapter 11 clauses, verify currency article by article.

3. Workmanship

1. Wire-pulling timing (GB 50166-2019 Clause 3.2.11): "Wiring in conduit or raceways shall be carried out after plastering and floor works; conduit and raceways shall be free of water and debris."
2. Joints (GB 50166-2019 Clause 3.2.13): "Cables in conduit or raceways shall have no joints or kinks. Conductors shall be reliably connected in junction boxes by welding, crimping, or terminals."
3. Conductor colors (GB 50166-2019 Clause 3.2.10): "Conductors in the same project shall be distinguished by color per use; conductors of the same use shall be the same color. The positive pole of power wiring shall be red, the negative blue or black."
4. Junction-box setting (GB 50166-2019 Clause 3.2.5): junction boxes shall be installed at convenient points where: (1) the run exceeds 30 m without bends; (2) exceeds 20 m with 1 bend; (3) exceeds 10 m with 2 bends; (4) exceeds 8 m with 3 bends.
5. Insulation resistance (GB 50166-2019 Clause 3.2.16): "After laying, the insulation resistance of each loop to earth shall be measured with a 500 V megger and shall not be less than 20 megohms."
6. Fill ratio and raceway filling (general wiring requirements): the total conductor section (including sheaths) in conduit shall not exceed 40% of the conduit bore, preferably not more than 8 conductors (GB 50575-2010 Clause 5.2.4); in raceways, total insulated-conductor section shall not exceed 40% of the raceway section, current-carrying conductors preferably not exceeding 30, control and signal circuits sharing the raceway not exceeding 50% (GB 50303-2015 Clause 14.2.5).

Applicable Boundaries

• Applies to wiring design, construction, and acceptance of automatic fire alarm systems (including linkage control) in industrial and civil buildings; does not cover all requirements for trunk power cables in substations/shafts or fire-power feeder selection.
• Version effect: GB 55036-2022 is fully mandatory; where inconsistent with GB 50116-2013, GB 55036-2022 prevails; some clauses of GB 50116-2013 Chapter 11 have been superseded (e.g., 11.2.5) — verify currency before use.
• Table 11.1.2 minimum-section values, burning-performance grades, and installation modes for a specific project follow the code tables and design documents; special locations such as above ceilings have separate calibers for exposed/concealed judgment.
• Costing note: the cable burning-performance grade (>= B2) and fire-resistance requirements affect material selection and price; price per the design-required grade.

Further Reading

• GB 55036-2022 General Code for Fire Protection Facilities, Chapter 12 (Clause 12.0.16 and neighbors)
• GB 50116-2013 Code for Design of Automatic Fire Alarm Systems, Chapter 11 "Wiring": 11.1.1, 11.1.2, 11.2.1, 11.2.3, 11.2.6
• GB 50166-2019 Standard for Construction and Acceptance of Automatic Fire Alarm Systems, Chapter 3 "Construction": 3.2.2, 3.2.5, 3.2.10-3.2.13, 3.2.16
• Companion general wiring standards: GB 50303-2015 Chapter 14; GB 50575-2010 Clause 5.2.4
• Commentary explanations (rationale of fire-resistant/flame-retardant requirements, the 30 mm cover, separate wiring for reliability) assist design disclosure and dispute resolution.